The LCC Flow Cytometry/Cell Sorting Shared Resource (FCSR) provides expertise for the innovative application of flow cytometry and cell sorting in order to fully exploit the capabilities of this technology for cancer research. The facility maintains two flow cytometer/cell sorters, a Becton Dickinson FACStarPlus and a Becton Dickinson FACSort, to provide services for a wide variety of projects. FCSR provides trained operators to ensure efficient and correct utilization of the instruments and the resultant data, to assist with staining of cell cycle samples and to assist in the development of new labeling protocols, customized to the investigator. In 2001, 44 investigators utilized the services of the FCSR. Of these, 38 investigators were LCC members and 33 of those had peer-review funded projects, representing 79% of resource use. The shared resource is able to provide flow cytometry analysis and cell sorting services as well as data analysis support to a wide variety of applications required by LCC members.